The problem statement: For each client, "determine if the difference between the [two most recent sales order] dates [exceeds eight] months."

Here's the sample sales data:

with
orders AS (
select 470873 as clientid, DATE'2010-02-18' as orddate from dual union all
select 479572 as clientid, DATE'2009-10-29' as orddate from dual union all
select 479572 as clientid, DATE'2008-03-06' as orddate from dual union all
select 470873 as clientid, DATE'2009-12-04' as orddate from dual union all
select 479572 as clientid, DATE'2003-09-23' as orddate from dual union all
select 470873 as clientid, DATE'2009-10-01' as orddate from dual union all
select 479572 as clientid, DATE'2003-07-17' as orddate from dual union all
select 470873 as clientid, DATE'2009-09-10' as orddate from dual union all
select 479572 as clientid, DATE'2002-11-15' as orddate from dual union all
select 470873 as clientid, DATE'2009-05-29' as orddate from dual
)